While I can't verify whether these demonstrations are indeed fake, I have a few observations. Demonstrator #1 (young fellow with jar head) tenses his neck before the blow. The severity of the punch is not known. You can take a bad punch in the throat and hurt later. This Also, it is possible that this fellow has natural attributes (height, recessed larynx, strong front neck muscles) that allow him to take such demonstrations. It is rarer that he can take shots to the throat and groin. Too many people think that martial arts is 100% development rather than a selection of the able.
The punch to the belly/solar plexus is unimpressive to a trained martial artist.
Taken ata face value, the groin shots are remarkable. I'd like to know more about the groin shots. There are many sleight-of-hand tricks performed by the obvious performer and the less-obvious trained member of the audience.